The invention relates to servomechanism systems and synchronized speech reproduction generally and, more particularly to such systems in which a dual track recording medium provides the speech signals and signal for synchronized simulated muscle motions separately, as in a talking doll or the like.
Various systems for combining visual and audio effects in a doll or other figure have been developed over the years. Of the known pertinent prior art arrangements, attention is drawn to U.S. Pats. Nos. 4,521,205; 3,287,849; 3,685,200; 4,207,704; 4,139,968; 3,199,248; and 3,427,745.
U.S. Pat. No. 4,521,205 describes a sound tape player having animated characteristics. A figure is "animated" in synchronism with sound reproduced from a pre-recorded magnetic tape cassette. Light sources are modulated by the reproduced sound waves in electrical form and the resulting light pulses are directed by light pipes to the eyes and mouth of the figure. No mechanical eye or other motions take place.
U.S. Pat. No. 3,287,849 describes a talking doll having synchronized mouth movement. Sound reproduced from a tape recording is emitted from a speaker and the same electrical signals driving the speaker are used to energize a solenoid connected to effect lip movements.
U.S. Pat. No. 3,685,200 similarly employs a pre-recorded tape cartridge and amplifier from which a speaker emits realistic speech sounds. Electro-magnet means and/or normally operated means are provided to cause doll body member movements relating to the sound from the speaker within.
U.S. Pat. No. 4,207,704 describes a movable member animal model which emits sounds from a speaker within from animal sounds pre-recorded on a tape. The speaker drive signals are also supplied to an audio signal level detector operating electromagnetic and hydraulic drives to open the animal mouth synchronously.
U.S. Pat. No. 4,139,968 discloses a puppet-like apparatus having a movable mouth (lower jaw) and a motor driven mechanical arrangement for opening and closing the mouth. Audio signals above a predetermined level, from either a connected microphone or a radio receiver within the puppet activate the mechanical jaw drive to simulate the type of mouth movements resulting from speech.
In U.S. Pat. No. 3,199,248 there is disclosed a talking parrott figure with microphone electronic circuits, and a loudspeaker within. An endless tape records speech directed to the microphone and is played back in parrott fashion. The reproduced speech from the endless tape is also used to activate a motor driven mechanism for flapping the parotts wings and opening and closing its beak.
Probably the most pertinent item of prior art is U.S. Pat. No. 3,427,745, a drummer toy with various drums "played" by the drummer. That patent discloses the use of a multi-channel magnetic tape. On one channel drum music is recorded and on the other control signals are recorded for programming the movement of the drummers through circuitry and electromagnets. The drum sounds and drummer motions are thereby synchronized.
A technique for controlling a machine tool by pulse-width modulated motor control is shown in U.S. Pat. No. 3,457,480. This technique which is otherwise known per se in the art, affords a method of proportional control applicable as background to that aspect of the combination of the invention.
Recently introduced talking and animated toys include a toy bear having battery powered circuits and servomechanisms for controlling eye and /or mouth movements from signals recorded on a control track of a dual track (stereo) tape cassette. The other track includes synchronized speech, reproduced and emitted by a loudspeaker within the toy bear. Several discretely controlled members, such as the head, eye lids and mouth of the bear are controlled from separable signals on the control track.
In the aforementioned toy bear, miniaturized servo-mechanisms are employed to act as artificial muscles responsive to the control track signals. These servo-mechanisms include miniature permanent magnet D.C. motors and are commonly of the type used in radio-controlled model aircraft and the like. Those servomechanisms are commonly identified as RC (radio controlled) servos. They include multiple gear trains to obtain sufficient mechanical advantage to move model aircraft control surfaces against aerodynamic reactive forces. The well known RC servo is relatively expensive to manufacture and assemble.
Speed of movement is not required in the usual RC servo applications, and in fact, fast action may not even by desirable. In the toy bear application, however, the eye, mouth and other movements must be relatively rapid to provide realism. The manner in which a new servomechanism, which is a part of the combination of the invention, improves the state of that aspect of the prior art will described hereinafter.